Winhelp32.exe File for Windows Vista -- How to Activate It Once You Have It

I realize that support for Vista from Microsoft has ended, but a friend has something he wants to do, and I thought maybe a user from the community might have an answer for it.

He has an old program from Win 95, a very specialized program and necessary to his work, which will load and run in its basic functions on Windows Vista 32-bit; however, the Help menus within the program won't work unless Vista has the WinHlp32.exe file, and without the Help menus working, the program limps along on one leg, and is only about 60% usable. And Vista didn't come with that file when purchased; one had to update from the Microsoft website to get it. But when my friend tried to update, he discovered that Microsoft had discontinued all support for Vista, and that he could no longer download the winhlp32.exe file. I think he was only a few months too late to get the updates, but late is late, and he's out of luck as far as Microsoft is concerned.

He managed to get a copy of the winhlp32.exe file from a third-party source. He virus-checked it and ascertained it's the original file produced by Microsoft, so it should be OK. However, right now it is just sitting in his Downloads folder, and he doesn't know how to "attach" it to the Windows system so that the Help menus will start working again.

Would he need to create a new subfolder under Windows called winhelp32, and then copy and paste the file there? Or should it be pasted directly into the C:/Windows folder? Or does it go somewhere else?

A further wrinkle is that the site that provided the file (exefiles.com) gives contradictory advice. On the one hand it says the file is the genuine Microsoft winhlp32.exe file for Vista, and is virus-free, malware-free, etc. On the other hand, it has a warning saying that *it does not recommend copying and pasting the file into the Windows folder*, as this could cause damage and in the worst case could cause the Windows Vista operating system to stop working!

He doesn't want to do damage to his system by messing up the Windows folder and maybe cause Vista to stop working, or malfunction. I don't know how to advise him. Does anyone here know how to do this?